The invention relates to an apparatus for supplying fuel for acceleration during the warm-up phse of an internal combustion engine in addition to the fuel supplied by a fuel supply system, the additional supply being introduced downstream of an arbitrarily actuatable throttle butterfly valve located in the induction tube of the engine.
It has been found that when an internal combustion engine is warming up, the fuel air mixture is steady state operation of the internal combustion engine can be adjusted to be substantially leaner than during a sudden opening of the throttle valve. Therefore, the emission of toxic matter and the fuel consumption can be reduced during the warm-up phase of an internal combustion engine by regulating a lean fuel-air mixture during the steady state operation of the internal combustion engine and to enrich the fuel air mixture for a short period of time during any sudden opening of the throttle butterfly valve.
In a known apparatus of this kind, the supply of fuel for acceleration in addition to the fuel air mixture prepared by the carburetor takes place downstream of an arbitrarily actuatable throttle valve in that a pneumatic control mechanism closes a pair of contacts in dependence on the change of the induction tube pressure whereby an electromagnet is energized and triggers the injection of the fuel for acceleration from a storage chamber out of an injection nozzle (see DT-AS No. 1 291 935). A disadvantage inherent in such an apparatus is that the mechanism responds to the opening motion of the throttle valve only after a certain amount of delay.